gps_reset.c

This a support library and assorted sample programs for interfacing

#include <stdio.h>
#include <stdlib.h>
#include "as_gps.h"
extern unsigned as_gps_snd_size[32];
#define sbsize(x) (as_gps_snd_size[x - 0xB0])

int main(int argc, char **argv)
{
    extern char *optarg;
    char *endp;
    int option;
    double latitude, longitude;
    int Lopt=0, lopt=0;
    char sndbuf[5];


    while ((option = getopt(argc, argv, "L:h?l:")) != -1) {
	switch (option) {
	case 'L':
	    longitude = strtod(optarg, &endp);
	    if (endp != NULL && toupper(*endp) == 'W')
	      longitude=-longitude;
	    else if (endp == NULL || (*endp && toupper(*endp)!='E')) {
		fprintf(stderr, "invalid longitude (-L) option;  %s\n", optarg);
		exit(1);
	    }
	    Lopt++;
	    break;
	case 'l':
	    latitude = strtod(optarg, &endp);
	    if (endp != NULL && toupper(*endp) == 'S')
	      latitude=-latitude;
	    else if (endp == NULL || (*endp && toupper(*endp)!='N')) {
		fprintf(stderr, "invalid latitude (-l) option;  %s\n", optarg);
		exit(1);
	    }
	    lopt++;
	    break;
	case 'h':
	case '?':
	default:
	    fputs("usage:  gps_reset [options] \n\
  options include: \n\
  -L longitude [ set longitude ] \n\
  -h           [ help message ] \n\
  -l latitude  [ set latitude ] \n\
", stderr);
	    exit(0);
	}
    }

  if(as_gps_open("/dev/gps"))
  {
    printf("Can't open device\n");
    exit(1);
  }

  as_gps_send_cmd(AS_GPS_SET_SYSTEM_RESET, sndbuf, sbsize(AS_GPS_SET_SYSTEM_RESET));
  if(Lopt && lopt) {
    option = (int)(latitude * 256.0 * 3600.0);
    sndbuf[2] = (option>>24);
    sndbuf[3] = (option>>16)&0xff;
    sndbuf[4] = (option>>8)&0xff;
    sndbuf[5] = (option)&0xff;

    option = (int)(longitude * 256.0 * 3600.0);
    sndbuf[6] = (option>>24);
    sndbuf[7] = (option>>16)&0xff;
    sndbuf[8] = (option>>8)&0xff;
    sndbuf[9] = (option)&0xff;

    as_gps_send_cmd(AS_GPS_SET_CURRENT_POSITION, sndbuf, sbsize(AS_GPS_SET_CURRENT_POSITION));
  }

  while(1)
  {
    void *data=NULL;
    unsigned char result = as_gps_handle_input(&data);

    if(result == AS_GPS_RCV_POSITION_DATA) // PositionData
    {
      as_gps_print_position_data((AS_GPS_PositionData *)data);  
    }
    else if(result == AS_GPS_RCV_RECEIVE_SAT) // SatPositionData
    {
      as_gps_print_receive_sats((AS_GPS_ReceiveSats *)data);  
    }

    free(data);
  }

  as_gps_close(); 
}